Cardiovascular System

Question 1

What does the cardiovascular system consist of?

Answer 1

The heart and blood vessels.

Question 2

What are the two aspects of the cardiovascular system?

Answer 2

Conduction System and mechanical pump

both must function for normal heartbeat to occur

Question 3

What makes up the conduction system?

Answer 3

SA node, AV node, bundle of HIS, right and left bundle branches and Purkinje fibres

Question 4

Where does the conduction system initiate?

Answer 4

In the SA Node (100bpm)

Question 5

How many BPM does the AV node depolarise to?

Answer 5

40-60bpm

Question 6

What is the equation for Cardiac output?

Answer 6

Heart Rate X Stroke Volume

Question 7

What is the equation for blood pressure?

Answer 7

HR X SV= CO and SVR

Question 8

What does SVR stand for?

Answer 8

Systemic Vascular Resistance

Question 9

What do we need to maintain blood pressure?

Answer 9

An effective pump and venous return (preload) and pressure in the system (Afterload)

Question 10

What are the two vital aspects of Cardiac Function?

Answer 10

Electrical activity and mechanical activity- if either fail the heart fails

Question 11

What does the cardiac system contain?

Answer 11

It’s own autorhymicity

Question 12

What is the SA Node?

Answer 12

It is normally the pacemaker of the heart 60-100bpm

Question 13

What can act as a secondary pacemaker if SA Node fails?

Answer 13

AV Node- 40-60bpm

Question 14

what can the cardiac conduction system be affected by?

Answer 14

Sympathetic and Parasympathetic nervous system

Question 15

In the hearts mechanical pump- why is the left ventricle wall thicker than the right ?

Answer 15

due to the need to generate higher pressures in systemic arteries

Question 16

What does myocardial contraction rely on?

Answer 16

Actin Myosin Sliding Filaments

Question 17

What is required for a strong contraction to occur?

Answer 17

Calcium as it binds to the actin

Question 18

What energy does contraction require?

Answer 18

high levels of energy in the form ATP- it also requires a huge amount of O2

Question 19

What is the hearts demand for blood supply?

Answer 19

5% total cardiac output

Question 20

what happens if there is a disruption to the supply of O2?

Answer 20

It can lead to arrthymias or damage to the muscle

Question 21

how much roughly of total body mass does the heart make up?

Answer 21

about 0.3%

Question 22

where is venous blood collected?

Answer 22

The Coronary Veins

Question 23

where does the venous blood drain directly to?

Answer 23

Drains directly into the right atria via the coronary sinus

Question 24

what are the two main phases of the Cardiac Cycle?

Answer 24

Diastole (relaxation) and Systole (contraction)

Question 25

How long on average does a full cycle take?

Answer 25

0.8 seconds

Question 26

what is the longest period of the Cardiac Cycle?

Answer 26

Diastole as this allows time for the atria and ventricles to fill

Question 27

what is the cardiac cycle driven by?

Answer 27

venous return from the superior and inferior vena cava

Question 28

what happens as the atria fills?

Answer 28

The volume exerts a pressure onto the AV valves

Question 29

What happens when the ventricles relax?

Answer 29

pressure gradient increases

Question 30

What happens when an MI affects the papillary muscles or valve infections?

Answer 30

It can cause malfunction of the valve (infective endocarditis)

Question 31

where do the veins carry blood to?

Answer 31

Back to the heart

Question 32

where do arteries carry blood from?

Answer 32

The Heart

Question 33

what has a vital role in maintaining BP?

Answer 33

Vascular System

Question 34

what affects Systemic Vascular resistance (SVR)?

Answer 34

dilation and constriction

Question 35

What is the filling of any heart chamber influenced by?

Answer 35

Venous return

Question 36

What are the two types of BP Control?

Answer 36

Neutral control and hormonal control

Question 37

Where is the nervous control managed in the brain?

Answer 37

It is managed by the cardiovascular centre in the medulla and pons of the brainstem

Question 38

Where are the cells that detect a reduction in renal blood flow and release renin?

Answer 38

Juxtaglomerular Apparatus

Question 39

Where does Renin convert Angiotensionogen to angiotensin I?

Answer 39

The Liver

Question 40

where is angiotensin I converted to angiotensin II?

Answer 40

The lungs

Question 41

Where is the antidiurectic hormone found?

Answer 41

posterior pituitary gland

Question 42

What does Angiotensin II stimulate?

Answer 42

It stimulates vasoconstriction of smooth muscle in the arterial circulation- increasing SVR

Question 43

What does ANP stand for?

Answer 43

Atrial Natriuretic Peptide

Question 44

What is ANP?

Answer 44

it is a hormone released in the heart when blood volume becomes great enough to stretch the atrial wall beyond normal